Conventional split-ring resonator BPFs enjoy the advantage of operation at high frequencies (e.g., in the gigahertz range) without being substantially affected by the proximity of parasitic components. Additionally, split-ring resonators have considerably less radiation losses than do straight microstrip resonators, thus enabling the use of microstrip technology in the implementation of BPFs. The use of stripline structure for this type of resonator would substantially eliminate small radiation losses associated with microstrip structure.